I'm having the exact same problem. My sound card is SigmaTel Audio. This is the only option it gives me under the "Select Recording Device" pulldown. The "Select Recording Source" pulldown only gives me Line In, Rear Mic and Microphone options. Rear Mic is selected by default, but I get silence using all three, regardless of the input levels. This is for anything I try to record online or with a music player. Not tried a microphone yet or another device like a tape recorder.

I purchased a new HP computer with Windows Vista. It has Realtek High Definition Audio card. I can not find the "Stereo Mix" in the properties of the Audio Manger. Can someone help me so I can record streaming audio? Your help is greatly appreciated.

Select sound from the control panel.
2. Select the recording tab.
3. Right click on the background of the tab and choose "show disabled devices."
4. Right click on Wave Out Mix (or Stereo Mix as it was called on my machine) and click enable.
5. Now it should work the same way as Wave Out Mix in Windows XP, allowing you to record any sound your computer makes.